Various types of valves incorporating sealing devices are known and widely used in the medical field. For example, mechanical sealing valves are required for various types of catheters, lavage devices, and endoscopy systems developed for a wide range of medical purposes. The valve sealing mechanisms typically preclude the flow of substances (gaseous or fluid) through the medical device in one direction, for example from the patient to the outside environment, while permitting the introduction or flow of desired substances (food, medication, etc.) in the other direction, for example into the patient through the medical device. Enteral feeding devices utilizing a gastrostomy catheter (xe2x80x9cfeeding tubexe2x80x9d) are examples of conventional medical devices utilizing a sealing valve to prevent gastric fluids, gases, or particles from unintentionally exiting the patient""s body via the catheter. U.S. Pat. Nos. 5,997,503 and 5,997,546, both owned by Applicants"" Assignee and incorporated by reference herein, disclose balloon catheters suitable for use as skin-level gastrostomy catheters for enteral feeding. Various other devices and catheters have also been proposed for gastrostomy feeding and are known to those skilled in the art.
Conventional sealing valves include duckbill valves, flap valves, slit seal valves, etc. Silicone rubber duckbill seals having durometer ratings of about 50 Shore and a wall thickness of about 0.040 inches have been employed in sealing gastrostomy catheters. Such sealing valves are typically kept closed via back pressure present on one side of the valve unless and until the seal is opened from the other side of the valve by insertion of a feeding tube or by a pressure differential across the seal.
Over time, conventional sealing valves may degrade or lose some of their flexibility (i.e., their ability to return to an initial sealing position after deflection) due to repeated or extended periods of opening of the valve. Also, in certain bodily environments, such as the acidic environment of the gastro-intestinal tract, exposure to the bodily fluids or stomach contents may have a corrosive or other negative effect on the sealing valve over time.
Thus, there is a need for an improved medical sealing valve for use in various medical devices, particularly gastrostomy catheter devices.
Objects and advantages of the invention will be set forth in part in the following description or may be apparent from the description or may be learned through practice of the invention.
According to the invention, an improved sealing valve assembly is provided for use in a wide array of medical products, including catheters, lavage devices, endoscopy systems, etc. The valve assembly according to the invention is not limited in its particular use and may be used in any medical product wherein it is necessary to permit fluid flow through the product in one direction while preventing backflow of fluids through the product in the opposite direction. For example, the valve assembly is particularly useful in a gastrostomy catheter. Accordingly, it should be appreciated that the present invention also includes medical products or devices incorporating the inventive valve assembly.
The valve assembly includes a valve housing defining a passageway therethrough. A valve member seated in the valve housing within the passageway. The valve member includes a peripheral portion spaced from the central axis of the valve assembly and two walls extending from the peripheral portion towards the central axis. The walls include ends that contact each other to preclude flow through the passageway toward the second end. The valve member further includes at least one stiffening member extending from at least one of the walls to urge the valve member toward the closed position.
The stiffening member may be a fin extending substantially perpendicular to the respective wall from which the stiffening member extends, or it may be a partial conical section. Two stiffening members may also be provided.
The invention will be described in greater detail below with reference to the figures.